如何使用R从一列的字符串中提取特定数字并将其存储在数据框的另一列中？

Question

I have a data frame which look like: Check The Data frame Here

I am facing an issue while extracting the value of ID from cs.uri.query column and storing that particular value in another column in same data frame. I tried a lot of methods like regex grep but still not able to solve. Basically what result i want to get would something be like: Result

Need help solve this issue.Thanks In Advance.

Answer 1

You could use the str_match function of the stringr library:

library(stringr) df$UserId <- str_match(df$cs.uri.query, "ID=([0-9]+)")[,2]

This will search for any matches to ID=<some number> and return the first bracketed match, ie the number.

Answer 2

Using gsub in base R...

df$UserID <- gsub(".*ID=([0-9]+).*","\\1",df$cs.uri.query)

This captures (in () ) the string of digits after ID= , and replaces the whole string (hence the .* at either side, which means any characters) with the first (and only) captured group \\\\1 .

I've not been able to test it on your data, but it should work.